Smoke filter

ABSTRACT

A smoke filter is provided which is adapted to be affixed to one end of a tobacco rod. The filter includes an elongated core piece formed from smoke impervious material and having a cylindrical upstream end section, a cylindrical center section of lesser diameter than said end section, and a fluted downstream end section. The fluted section is provided with a first set of elongated flutes extending downstream from the center section and a second set of elongated flutes annularly offset from said first set and extending downstream therefrom. One set of flutes is of greater depth than the other and forms a trap for smoke particles. The core piece is encompassed by an inner sleeve provided with a plurality of perforations arranged in encircling relation with respect to the center section. The inner sleeve cooperates with the center section to form a shallow annular first passageway. An outer sleeve encompasses the inner sleeve and is spaced therefrom to form an annular second passageway which communicates with the first passageway only through the perforations. The smoke flows through the perforations as high velocity jets which impinge against the exterior of the core piece center section. Subsequent to the jet impingement, the smoke flows downstream past the fluted end section.

United States Patent Pinkham R. J. Reynolds Tobacco Company, Winston-Salem, N.C.

[22 Filed: Feb. 19,1910

211 Appl.No.: 12,745

[73] Assignee:

[52] U.S.Cl ..131/261B,131/201, 131/210, 131/212 A [51] Int. Cl ..A24d 01/04, A241 07/04, A24f 13/06 [58] FieldofSearch ..l31/10.5,261B,201,210, 131/213, 216, 218

[56] References Cited UNITED STATES PATENTS 3,577,996 5/1971 Sherrill ..l3l/10.5 2,954,787 10/1960 Leben ..13l/10.5 X 1,582,971 5/1926 Conley ..131/201 3,472,238 10/1969 Blount et al. 131/201 X 3,174,487 3/1965 Missler ...l31/210 X 973,870 10/1910 Matson ..131/210 X 3,428,050 2/1969 Kandel ..131/10.5 X

FOREIGN PATENTS OR APPLICATIONS 570,085 6/1945 Great Britain ..131/212 A 1,508,121 11/1967 France ..131/261 B Feb. 1, 1972 Primary ExaminerSamuel Koren Assistant Examiner-.l. F. Pitrelli AttorneyPendleton, Neuman, Williams & Anderson [5 7] ABSTRACT A smoke filter is provided which is adapted to be aflixed to one end of a tobacco rod. The filter includes an elongated core piece formed from smoke impervious material and having a cylindrical upstream end section, a cylindrical center section of lesser diameter than said end section, and a fluted downstream end section. The fluted section is provided with a first set of elongated flutes extending downstream from the center section and a second set of elongated flutes annularly offset from said first set and extending downstream therefrom. One set of flutes is of greater depth than the other and forms a trap for smoke particles. The core piece is encompassed by an inner sleeve provided with a plurality of perforations arranged in encircling relation with respect to the center section. The inner sleeve cooperates with the center section to form a shallow annular first passageway. An outer sleeve encompasses the inner sleeve and is spaced therefrom to form an annular second passageway which communicates with the first passageway only through the perforations. The smoke flows through the perforations as high velocity jets which impinge against the exterior of the core piece center section. Subsequent to the jet impingement, the smoke flows downstream past the fluted end section.

5 Claims, 9 Drawing Figures PATENTED FEB H972 SHEET 2 0F 2 SMOKE FILTER BACKGROUND OF THE INVENTION Various smoke filters for cigarettes, cigars, pipes, etc., have heretofore been provided, however, because of certain design characteristics they are beset with one or more of the-following shortcomings: (a) they are formed of numerous component parts of special design which increase the cost of the filter; (b) the assembling of the filter is slow and complex and is not compatible with the manufacturing methods and techniques utilized in forming the tobacco rod; (c) the pressure drop across the filter increases materially during smoking causing discomfort to the smoker; and (d) the filter is ineffective in removing liquid and/or solid particles from the smoke.

SUMMARY OF THE INVENTION Thus, it is an object of this invention to provide a smoke filter which avoids the aforementioned shortcomings that have beset prior filters.

It is a further object of this invention to provide a smoke filter which may be readily tested before being affixed to the end ofa tobacco rod.

It is a still further object of this invention to provide a smoke filter which may be readily assembled with automatic equipment, the function and operation of which is well known in the cigarette-making set.

Further and additional objects will appear from the description, accompanying drawings, and appended claims.

In accordance with one embodiment of the invention a smoke filter is provided which is adapted to be affixed to the end of a tobacco rod. The filter includes a first sleeve, a second sleeve disposed within the first'sleeve and spaced therefrom to form an annular first passageway. The second sleeve encompasses a smoke-impervious core piece which includes a cylindrical upstream end section, a cylindrical center section of lesser diameter than the upstream end section, and a fluted downstream end section. The second sleeve is provided with a sleeve-encircling row of perforations in registered relation with the core piece center section. The second sleeve cooperates with the core piece center section to form a shallow annular second passageway which communicates with the first passageway only through the row of perforations. The fluted end section of the core piece is provided with a first set of elongated flutes and a second set of elongated flutes disposed longitudinally of said first set and angularly offset with respect thereto. The depth of said first set of flutes being greater thanthe depth of the second set of flutes, The sets of flutescooperate with the second sleeve to form a plurality of narrow passageways in communication with the shallow annular passageway.

DESCRIPTION For a more complete understanding of the invention reference should be made to the drawings wherein:

FIG. 1 is an enlarged fragmentary longitudinal sectional view of one form of the-improved filter shown affixed to one end ofa tobacco rod.

FIGS. 2, 3, and 4 are enlarged sectional views taken along lines 2-2, 3-3, and 4-4, respectively, of FIG. 1.

FIG. 5 is a right end view of FIG. 1.

FIG. 6 is a perspective top view of an elongated core member from which a plurality of core pieces are subsequently formed.

FIG. 7 is similar to FIG. 6, but showing an inner sleeve member encompassing the core member,

FIG. 8 is similar to FIG. 7, but showing spacer members applied to the exterior of the inner sleeve member.

FIG. 9 is similar to FIG. 8, but showing a second sleeve in encompassing relation therewith.

Referring now to the drawings and more particularly to FIG. 1, one form of the improved smoke filter 10 is shown which includes first sleeve 11 of tipping paper or the like, a second sleeve 12 which supportingly engages the. interior surface of sleeve 11, a third or inner sleeve 13 which is disposed within the second sleeve 12 and is held in spaced relation therewith by a spacer piece 14 which encompasses the downstream end of the inner sleeve 13. The spaced second and inner sleeves I2 and 13, respectively, cooperate to form an annular first passageway 15, the upstream end ofwhich communicates with the tobacco core 16 of the tobacco rod 17 to which the filter 10 is affixed by the sleeve 11.

The inner sleeve 13 snugly encompasses an elongated core piece 18 which is formed ofa smoke-impervious material such as foam plastic which has been extruded and then afterformed in a manner well known in the extruding art. The core piece 18, however, if desired, may be molded or formed by various other well known means.

The core piece 18 includes a cylindrical upstream end section 20 which is in abutting relation with the downstream end of the tobacco rod. The diameter of end section 20 is less than the outer diameter of the tobacco core 16. Cylindrical section 20 is in supporting engagement with one end of inner sleeve 1 The core piece 18 is also provided with a cylindrical center section 21 which is of lesser diameter than cylindrical section 20 of piece 18.

The downstream end section 22 of the core piece is fluted and includes a first set of symmetrically arranged flutes 23a which are separated from one another by elongated ribs 23b. The ribs 23b supportingly engage the interior surface of inner sleeve 13.

Spaced downstream of the first set of flutes 23a and annularly offset with respect thereto is a second set of flutes 24a which are separated from one another by a plurality of symmetrically arranged elongated ribs 24b. As seen in FIGS. 4 and 5, the depth of the first set of flutes 23a is greater than the depth of the second set of flutes 24a; thus, flutes 23a function as traps for the various particles which have become deposited on the exterior ofthe core piece center section 21 and thereby prevent any of the deposited particles from finding their way out the downstream end of the filter and into the smokers mouth.

By reason of the angular offsetting of the ribs 23b and 24b, a tortuous smoke path is formed in the downstream end section of the core piece.

The inner sleeve 13 is provided with a plurality of small perforations 25 (diameter range 0.002 inch to 0.012 inch) which are arranged in a sleeve-encircling row. The row is in registration with the core piece center section 21. The number of perforations included in the row may vary from 10 to 150.

The inner sleeve 13 cooperates with the core piece center section 21 to form a shallow annular second passageway 26. The radial distance the exterior of the center section 21 is from the perforations 25 may vary from 0.008 inch to 0.022 inch. Thus, when smoke is drawn through the filter 10, it passes from the passageway 15 through the perforations 25 in the form of high-velocity jets into passageway 26 with the result that liquid and/or solid particles entrained in the smoke jets impinge against and are deposited on the exterior of the center section 21 before the smoke continues through passageway 26 and the narrow passageways formed by the sets of flutes 23a and 240.

In forming the improved filter, an elongated core member 27, see FIG. 6, is first provided which in the illustrated embodiment would be referred to as a four-up unit; that is to say, it has a length equivalent to four core pieces 18. The length of core member 27 may be longer or shorter than that illustrated and will depend upon the type of automatic equipment used during the assembly of the filter. In the illustrated member 27, there is provided at each end, a cylindrical end section 20. Disposed inwardly of each end section is a center section 21 of appropriate length. Arranged inwardly of each section 21, is a double-length fluted end section 22 which is subsequently cut at midlength to form two fluted end sections 22 of proper length. Disposed inwardly of each double-length fluted section I 22 is another center section 21 of proper length. At the center of member 27 is provided a double-length cylindrical end section The latter is subsequently cut to form two cylindrical sections 20 of proper length. As previously mentioned, the core piece may be formed by extrusion and afterforming from a foam plastic material (e.g., polystyrene).

Subsequent to the formation of the core member 27 it is snugly encompassed by an elongated sleeve unit 13' formed of a thin web (e.g., from 0.0005 to 0.004 inch thick) of plastic, paper or foil which had previously had the sleeve-encircling rows of perforations formed therein. It will be noted that the rows of perforations are arranged in registered relation with respect to the cylindrical center sections 21 formed in the member 27. Aside from the rows of perforations, the sleeve unit 13' is impervious to smoke.

Following the assembly of sleeve unit 13' about core member 27, double-length spacer units 14 are applied in iongitudinally spaced relation to the exterior of the sleeve unit 13 so that a spacer unit will be coextensive with each doublelength fluted end section 22.

Each spacer unit 14 may be formed by successively wrapping the sleeve unit with a narrow web of thin material a sufficient number of times so as to build up the necessary thickness. Once the spacer units 14 are in place, a second sleeve unit 12', see FIG. 9, is brought into encompassing relation with the unit shown in FIG. 8. The second sleeve unit 12 is formed from a web of plastic, paper, or foil which is of greater thickness than sleeve unit 13 and thus is more rigid than the latter. The unit, as seen in FIG. 9, may be readily tested while in such a state to determine whether the proper draw (suction) can be effected through the unit. If by chance there is a misalignment of the rows of perforations with the center sections 21 thereby causing blockage of some, or all, of the perforations, this condition would be readily apparent from said test and thus, said unit would automatically be discarded before the tobacco rods are affixed thereto. In addition to providing a means for suction-testing the unit, the sleeve unit 12 provides an added support for the tipping paper thereby minimizing distortion of the tipping paper sleeve 11 by the lip pressure of the smoker,

in instances where suction-testing of the unit is not desired before tobacco rods are affixed thereto, or where the tipping paper sleeve 11 is sufficiently stiff to withstand normal lip' pressure of the smoker, the second sleeve unit 12 may be omitted.

Once the unit of FIG. 9 has been formed, it is then severed along line X into a pair of two-up units provided at each end with a cylindrical end section 20. To the opposite ends of each two-up unit is positioned in abutting endwise relation, a pair of tobacco rods 17. Once the rods are in place, a sleeve 11 of tipping paper or the like is applied to affix the rods to each end of the two-up units. The final step of assembly is cutting each two-up unit at its midpoint which coincides with the midlength Y-Y ofeach double-length spacer unit 14', as seen in FIG. 8.

The expeditious manipulation of four-up and two-up units by automatic equipment is well known in the cigarette-making art and thus, may be readily integrated in established cigarette-making procedures.

Thus, with the improved filter 10, there is no longer need for an Estron (cellulose acetate) plug or the like to be positioned in tandem relation with the downstream end of the core piece 18 in order to prevent the particles deposited on the core piece center section from reaching the smokers mouth. By reason of the elimination of the conventional plug, the cost of the filter is substantially reduced and the assembly of the filter is greatly simplified. The shape and size of the improved filter may be varied from that shown without departing from the scope of the invention.

lclaim:

I. A smoke filter adapted to be affixed to one end of a tobacco rod, said filter comprising an outer sleeve; an inner sleeve disposed within said outer sleeve and cooperating therewith to form an annular first passageway terminating at one end of the tobacco rod and an elongated smoke impervious core piece disposed within and encompassed by said inner sleeve; said core piece being provided with a cylindrically shaped upstream end section, a cylindrically shaped center section of lesser diameter than said upstream end section, and a fluted downstream end section, said downstream end section having a first set of flutes extending a predetermined distance downstream from said center section, and a second set of flutes annularly offset from said first set and extending downstream therefrom, the flutes of one set being of greater depth that the flutes of the other set; said core piece center section cooperating with said inner sleeve to form a shallow annular second passageway communicating with said first passageway only through a plurality of perforations formed in said inner sleeve and arranged in encircling relation with respect to said core center section, said annular first passageway including an annular smoke impervious spacer disposed downstream of said inner sleeve perforations, said spacer encompassing said inner sleeve and in supporting engagement with said outer sleeve; said sets of flutes cooperating with said inner sleeve to form a set of elongated narrow third passageways communicating with said second passageway and a set of elongated narrow fourth passageways communicating with said third passageways; the smoke from the tobacco rod being adapted to flow from said first passageway through said inner sleeve perforations in the form of high-velocity jets into said passageway and impinge against the exterior of said core piece center section and deposit thereon liquid and solid particles entrained in the smoke.

2. The smoke filter of claim 1 wherein the depth of the first set of flutes is greater than the depth of the second set of flutes.

3. The smoke filter of claim 2 wherein the adjacent flutes of each set of flutes are separated by elongated ribs which supportingly engage said inner sleeve.

4. The smoke filter of claim 1 wherein said spacer is substantially coextensive with said core piece downstream end section.

5. The smoke filter of claim 1 wherein said outer sleeve includes a reenforcing sleeve coextensive with said core piece. 

1. A smoke filter adapted to be affixed to one end of a tobacco rod, said filter comprising an outer sleeve; an inner sleeve disposed within said outer sleeve and cooperating therewith to form an annular first passageway terminating at one end of the tobacco rod; and an elongated smoke impervious core piece disposed within and encompassed by said inner sleeve; said core piece being provided with a cylindrically shaped upstream end section, a cylindrically shaped center section of lesser diameter than said upstream end section, and a fluted downstream end section, said downstream end section having a first set of flutes extending a predetermined distance downstream from said center section, and a second set of flutes annularly offset from said first set and extending downstream therefrom, the flutes of one set being of greater depth that the flutes of the other set; said core piece center section cooperating with said inner sleeve to form a shallow annular second passageway communicating with said first passageway only through a plurality of perforations formed in said inner sleeve and arranged in encircling relation with respect to said core center section, said annular first passageway including an annular smoke impervious spacer disposed downstream of said inner sleeve perforations, said spacer encompassing said inner sleeve and in supporting engagement with said outer sleeve; said sets of flutes cooperating with said inner sleeve to form a set of elongated narrow third passageways communicating with said second passageway and a set of elongated narrow fourth passageways communicating with said third passageways; the smoke from the tobacco rod being adapted to flow from said first passageway through said inner sleeve perforations in the form of high-velocity jets into said passageway and impinge against the exterior of said core piece center section and deposit thereon liquid and solid particles entrained in the Smoke.
 2. The smoke filter of claim 1 wherein the depth of the first set of flutes is greater than the depth of the second set of flutes.
 3. The smoke filter of claim 2 wherein the adjacent flutes of each set of flutes are separated by elongated ribs which supportingly engage said inner sleeve.
 4. The smoke filter of claim 1 wherein said spacer is substantially coextensive with said core piece downstream end section.
 5. The smoke filter of claim 1 wherein said outer sleeve includes a reenforcing sleeve coextensive with said core piece. 